1. Field of Invention
The invention relates to a positioning method, and more particularly, to a positioning method for a touch display panel.
2. Background of the Invention
With the advancement of the electronic technology and the display technology, great breakthroughs have been brought to the existing human-machine interfaces that are no longer limited to mice or operating keyboards. Most electronic devices, such as notebook computers, mobile phones, or portable multimedia players, have touch panels serving as innovative input interfaces in replacement of conventional keyboards.
Based on the principle of designing touch display panels in different touch sensing modes, the touch display panels may be categorized into resistive touch display panels, capacitive touch display panels, optical touch display panels, sound wave touch display panels, electromagnetic touch display panels, and so on. Here, the resistive touch display panels and the capacitive touch display panels are the mainstream products. From another aspect, the touch display panels may be categorized into an adhesive type and a built-in type according to the structure of the touch display panels. In a capacitive touch panel, a uniform low-voltage electric field is generated between an inner conductive layer and an outer conductive layer. When a conductor (e.g., a user's finger) touches the panel, the resultant electrostatic binding may lead to a slight variation of capacitance. Through measurement of a position of the variation of capacitance of the panel, the coordinates of the touch position on the panel may be determined.
A conventional capacitive touch display panel is constituted by a touch panel and an underlying display panel. The touch panel is disposed above the display panel, and therefore transmittance of the display panel is apt to be reduced. If the display panel is disposed in front of the touch panel to improve the transmittance of the display panel, a touch signal can only be transmitted to the touch panel through the display panel, and thus the positioning accuracy is not as favorable as expected. Therefore, how to enhance the positioning accuracy of the capacitive touch display panel is one of the issues to be dealt with instantly in the field of the capacitive touch display panel.